Synthesis of Mn-CeOx/cordierite catalysts using various coating materials and pore-forming agents for non-methane hydrocarbon oxidation in cooking oil fumes

Cooking oil fumes (COFs) as an important source of volatile organic compounds (VOCs) in metropolitan areas is poisonous to the environment and human health, and the removal rate of Non-methane Hydrocarbon (NMHC) in COFs was used to verify the activity of catalysts made to depurate COFs. The textural properties of cordierite are limitation to the catalyst's performance. Therefore, in this paper, coating the cordierite to improve its surface properties was investigated. The experiment results and characterization data revealed that TiO₂ was a better coating material because of coating on TiO₂ can improve the surface morphology better than that of Al₂O₃. The SEM and BET data of the materials synthesized with different content of CTAB showed that 10?wt% additive amount of pore-forming agent had a better textural properties than other additive amount of pore-forming agents. It is clear that the S_BET and D_V of the catalysts were significantly increased, and the catalyst exhibited smaller particle size and more developed pore structure after ultrasonic treatment which proving that ultrasound can enhance the catalyst's catalytic activity. It is obviously that the catalyst synthesized with CTAB had best pore structure and Mn₄Ce₁/Ti/NC-CTAB-U exhibited the best performance for catalytic combustion of NMHC with the removal rate was 93.6% at 400?°C.     

炼油厂恶臭废气综合治理技术的研究Ⅱ.装车装船逸散废气治理技术

研究了炼油厂装车装船排放气组成和排放规律,对装载场合废气收集方式、引气控制、治理技术进行了分析和工业化试验研究。结果表明:装车装船逸散废气中非甲烷总烃浓度随装卸时间的延长而逐渐升高,废气收集采用引气式压力控制能实现流量自动控制;采用低温馏分油临界吸收-吸附技术对码头装船逸散废气进行回收治理,净化气中非甲烷总烃浓度低于6.1×10~3 mg/m~3,非甲烷烃总烃净化效率大于99.3%;采用低温馏分油临界吸收-催化氧化技术对装车栈台逸散废气进行回收净化治理,净化气中非甲烷总烃浓度不大于7.9mg/m~3,净化效率接近100%。     

Optimization of a heavy-duty compression-ignition engine fueled with diesel and gasoline-like fuels

Optimal injection strategies for a heavy-duty compression-ignition engine fueled with diesel and gasoline-like fuels (#91 gasoline and E10) and operated under mid- and high-load conditions are investigated. A state-of-the-art engine CFD tool with detailed fuel chemistry was used to evaluate the engine performance and pollutant emissions. The CFD tools feature a recently developed efficient chemistry solver that allowed the optimization tasks to be completed in practical computer times. A Non-dominated Sorting Genetic Algorithm II (NSGA II) was coupled with the CFD tool to seek optimal combinations of injection system variables to achieve clean and efficient combustion. The optimization study identified several key parameters that influence engine performance. It was found that the fuel volatility and reactivity both play important roles at the mid-load condition, while the high-load condition is less sensitive to the fuel reactivity. However, high volatility fuels, such as gasoline and E10, were found to be beneficial to fuel economy at high-load. The study indicates that with an optimized injection system gasoline-like fuels are promising for heavy-duty CI engines due to their lower NOx and soot emissions and higher fuel economy compared to conventional diesel fuels. However, the high in-cylinder gas pressure rise rate associated with Partially Premixed Combustion of gasoline-like fuels can become problematic at high-load and the low-load operating limit is also a challenge. Potential solutions are discussed based on the present optimization results.     

甲烷和非甲烷在线色谱的研制及应用

基于空气中甲烷和非甲烷总烃实时监测的需求,研发了采用阀进样和反吹切换技术的在线色谱监测仪。本文介绍了仪器的主要架构和技术特点,实验室性能测试结果和在科研、大气环境监测及化工园区污染物监测领域的应用效果。测试数据和现场应用结果表明该在线色谱仪具有分析时间短（〈3min）,测量精度高、线性范围宽、普适性强等特点,技术指标等于和部分优于国外先进产品,完全满足空气中甲烷和非甲烷总烃在线监测的要求。     

石油化工生产中气态非甲烷烃的排放及其防治对策

对石油化工生产所排放的气态非甲烷烃(NMHC)进行了综合研究,从来源、采样分析方法及产生原因等几方面阐述了我国石化生产中气态NMHC污染控制方面存在的问题,提出了适合我国国情和世界环保要求的污染防治对策.     

The potential of di-methyl ether (DME) as an alternative fuel for compression-ignition engines: A review

This paper reviews the properties and application of di-methyl ether (DME) as a candidate fuel for compression-ignition engines. DME is produced by the conversion of various feedstock such as natural gas, coal, oil residues and bio-mass. To determine the technical feasibility of DME, the review compares its key properties with those of diesel fuel that are relevant to this application. DME’s diesel engine-compatible properties are its high cetane number and low auto-ignition temperature. In addition, its simple chemical structure and high oxygen content result in soot-free combustion in engines. Fuel injection of DME can be achieved through both conventional mechanical and current common-rail systems but requires slight modification of the standard system to prevent corrosion and overcome low lubricity. The spray characteristics of DME enable its application to compression-ignition engines despite some differences in its properties such as easier evaporation and lower density. Overall, the low particulate matter production of DME provides adequate justification for its consideration as a candidate fuel in compression-ignition engines. Recent research and development shows comparable output performance to a diesel fuel led engine but with lower particulate emissions. NO_x emissions from DME-fuelled engines can meet future regulations with high exhaust gas recirculation in combination with a lean NO_x trap. Although more development work has focused on medium or heavy-duty engines, this paper provides a comprehensive review of the technical feasibility of DME as a candidate fuel for environmentally-friendly compression-ignition engines independent of size or application.     

大气环境影响评价中挥发性有机化合物与非甲烷总烃的异同

分别从定义、监测与分析方法、执行标准等3个角度深入系统地分析了挥发性有机化合物(VOCs)和非甲烷总烃(NMHC)的异同。结果表明,NMHC的范畴在是否应包括含氧烃方面尚存在争议;目前VOCs和NMHC的实际监测分析方法与相关标准中规定的方法不完全一致;VOCs和NMHC参照执行的环境质量标准和排放标准较为混乱。对此,在大气环境影响评价中建议同时监测VOCs和NMHC,并制订统一的环境标准。     

Correlation of the ratio of non-methane hydrocarbon and nitrogen oxide concentrations in the atmosphere and outdoor environment

A correlation between atmospheric pollution due to the emission of volatile organic compounds (VOC) and the non-methane hydrocarbon/nitrogen oxide (NMHC/NO_x) ratio has been determined. We supposed the source of NMHC in a region using the NMHC/NO_x ratio without needing to consider diffusion and dilution due to meteorological conditions. At general measurement stations in Neyagawa and Higashiosaka cities in Osaka Prefecture, the NMHC/NO_x ratio was high in summer though the NMHC and NO_x concentrations were high in early winter. Conversely, measurements of the ratio at a traffic measurement station in Shijonawate did not have this pattern. That is, NMHC emission increased with the temperature in Neyagawa and Higashiosaka. It was concluded the waste plastic processing facility increased the NMHC/NO_x ratio by comparing the change in the annually averaged NMHC/NO_x ratio at Neyagawa and Higashiosaka with the developments of disposal and treatment facilities in Neyagawa. In the case of Neyagawa, ventilation is not suitable for improving indoor air quality, because the outdoor pollution level can be higher than that indoors. The NMHC/NO_x ratio is a useful index to evaluate the change in the regional environment due to VOC pollution, and it can judge whether outdoor air can improve indoor air quality by ventilation.